Hydrothermal characteristic of pulsating heat pipe arranged in tubular loop

Effective rotor cooling poses significant difficulty in thermal management of an electric motor (EM). Dissipating heat generated in an EM rotor using compact cooling structure with minimum power consumption has led to present innovative tubular pulsating heat pipe (TPHP) that capitalizes latent heat transmissions afforded by the interconnected channels looped in tubular form. This is the first application of a tubular loop PHP design for rotating component cooling. Numerical study elucidates the interfacial dynamics for addressing the cooling attributes to transient heat transfer responses. Experimental study underscores the steady-state heat transfer performance of the stationary TPHP, made of stainless steel pipe with thermal conductivity about 15 Wm-1K-1, highlighting the thermal resistance networks at controlled heating powers (Q) and cooling conditions. Overall thermal resistances, which decrease withQof 25-55 W, fall between 0.76 and 1.27 KW-1, giving rise the effective thermal conductivity of 84-333 Wm-1K-1. Experimental findings advocate for verifying the TPHP design and propose promising directions for future research concerning rotational effect in rotor cooling efficacy. Empirical correlations that evaluate dimensionless thermal resistance and effective thermal conductivity of TPHP are developed to bridge the gap between implementing thermal simulation for an EM with present TPHP in rotor and the underlying two-phase flow phenomena, contributing to both heat transfer knowledge and engineering applications.